I was introduced to Ivan's transformers in a friend's project - and - there is no way that I shall ever go back to any opamp - the only way that comes to mind to describe what the transformers have done to the music is - taking away any digital artifacts (for the lack of a better word) - sound simply more natural without any digital "harshness". So, yes, I am a very happy customer.

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Hi guys, I got my trafos from Ivan. They are great! I love them! 
Out of those three stages I tested Ivans trafos was absolutelly the best! I would say the most musical and natural sound. I really recommned you try them.

Your transformers sound excellent.

Many big thanks to Ivan, the transformer really sound fantastic!

When I turned it on for the first time I couldn't tear myself away for 5 hours 

The sound was a little different, first impression: more high frequencies and less bass. After a while I realized that the bass is not lacking, it is different, strong but more punctual, it does not cover other ranges. Better for me.

What surprised me was the space. I listen on headphones and suddenly some new sounds appeared somewhere in the back of my head.
Amazing....

Super product...

I ordered a pair of the bigger transformers (1:15) that Ivan offers, for my TDA1541A dac (in simultaneous mode, with Andrea Mori external clocks). I had previously used the 'smaller' 1:22 versions, and was very happy with the timbre, depth and overall sound they provided.
I hooked them up and used a 33ohm I/V resistor that Ivan also makes and after a week of listening can only say the following:
They are Absolutely Brilliant!
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Hello, just to share my experience with 0.5+0.5 : 22 transformers on a SM5865 DAC Chips. They are really superb , sound is more transparent and 3D than ever before. Tried many kinds of Opamps on my DAC output - none of them can compare to this transparency. Of course i have weak output ( 0,47V) and a driver / buffer is needed to match my amp impedance, but once everything is set right - the potential of this transformer i/v is superb. Bravo!

I think that's what makes Ivan amazing to deal with. He has answered 10's if not a 100+ questions from me and studied several iterations of my amps, speakers, source and gain strategy for my system. Strongly recommended.

Every instrument just sound as what it should be. 'Stage' is just brilliant. You can hear every layer. Feedback #1

Ivan's output transformer is excellent suited for the ES9038Pro dac chip. This dual mono ES9038pro gives me the best DAC sound I have ever heard. Feedback #2

I wholeheartedly recommend his trafos for dacs. Once I am settled with the trafo loading, I will recommend the same to other DDDAC users as well who are on a budget and don't want to consider buying 700-1000USD trafo pairs. Ivan's trafos are amazing.
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sound from the trafo strong, dynamic, open, nice for the ear, lovely sound
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The transformers produced by Ivan Biyak are a high quality product because the distortion is half of the others with a higher output level.

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